Roller mill drive

ABSTRACT

Drive for roller mills having a horizontally disposed grinding vessel rotatable about a vertical axis and rollers rolling in the vessel that rotate about stationary axles which are under pressure, where one part of the support of the outer periphery of the grinding vessel constitutes the rotor of the electromotor which drives the vessel and which carries the rotor winding is encompassed by a horizontally disposed stationary stator supported directly in the housing of the mill.

United States Patent Schauer [54] ROLLER MILL DRIVE [72] Inventor:Siegfried Schauer, Kaiserslauternl-lohenecken, Germany [73] Assignee:Firma Gebr. Pfeiffer Barbarossawerke A.G., Kaiserslautern am Pfalz,Germany [22] Filed: Nov. 16, 1970 [21] Appl. No.: 89,656

[30] Foreign Application Priority Data Nov. 15, 1969 Germany ..P 19 57580.5

52 u.s.c1 ..24l/12l,310/66,310/157 [51] 1111.01. usozc s/oo 5sFieldofSearch ..310/66,l5,7,96,9l;24l/l76,

[56] References Cited 8 UNITED STATES PATENTS 2,909,330 10/1959 Hardinge..241/121 3,083,920 4/1963 Schauer ..241/121 1451 Apr. 25,1972

2,635,198 4/1953 2,722,612 11/1955 Danel ...3l0/l57 3,549,922 11/1970Kostin ..310/157 FOREIGN PATENTS OR APPLICATIONS 771,185 3/1957 GreatBritain ..241/121 561,582 8/1958 Canada ..241/121 Primary E.\'aminer.l.D. Miller Assistant Examiner-R. Skudy Attorney-Robert H. Jacob [57]ABSTRACT Drive for roller mills having a horizontally disposed grindingvessel rotatable about a vertical axis and rollers rolling in the vesselthat rotate about stationary axles which are under pressure, where onepart of the support of the outer periphery of the grinding vesselconstitutes the rotor of the electromotor which drives the vessel andwhich carries the rotor winding is encompassed by a horizontallydisposed stationary stator supported directly in the housing of the mill2 Claims, 1 Drawing Figure Wieseman ..310/157 ROLLER MILL DRIVEBACKGROUND OF THE INVENTION The present invention relates to rollermills and is particularly concerned with drive means for verticallydisposed roller mills. More particularly, the invention relates to drivemeans for roller mills having a vertical axis, of the type known asresilient rollers and/or resilient force mills. These mills are equippedwith a grinding container or vessel or a grinding bed,

and rollers that roll on this bed which rotate about a stationary axisand are spring biased. The grinding rollers thus are pressedagainst thegrinding vessel and the material to be processed is crushed and groundbetween them.

The grinding vessel or bed is driven in a conventional manner by anelectromotor with an intermediate special trans mission and rotated, andthe rollers that are pressed downwardly from the top are carried alongby friction.

Depending on the qualities of the material being ground which issupplied in gritty or irregular particle form, there develop during theprocess of the material being ground, correspondingly large shocks whichare transferred to the special transmission. These shocks expressthemselves on the one hand in axial thrusts against the transmission,while on the other hand torsional or rotary oscillations develop, i.e.loads on the transmission in tangential direction whereby the gears ofthe transmission are subjected to excessive wear.

In extreme cases thereis the possibility of a rocking movement due tothese oscillations in which connection parts of the transmission can becompletely destroyed.

The special transmissions which are in question here with theirrelatively high reduction ratios and the problem of transmitting largeforces are very expensive. This applies not only to the gearsthemselves, but also to repair parts. Besides, extremely high costs canresult, especially secondary damage when a mill of this type is out oforder due to damage to the transmission.

The invention is based on the problem of eliminating this danger pointof the aforementioned mills and to find ways and means how to adapt thedrive to the severe operating conditions and to improve theconstruction.

SUMMARY OF THE INVENTION in accordance with the invention this object isobtained with a drive for roller mills having a vertical axis, in thatan area of the outer periphery of the grinding vessel is constructed inthe form of the rotor of an electromotor which is surrounded by a statorfixedly mounted in horizontal position in the housing.

By means of this form of construction, the expensive transmission thatwas formerly necessary and which is subject to break downs requiringrepairs becomes entirely superfluous.

Furthermore, this form of construction permits an advantageousjournalling of the grinding vessel to absorb the axial forces thatarise. Thus, torsional oscillations and the forces connected therewithcan no longer be transferred in tangential direction onto components ofthe transmission and also axial forces become ineffective with respectto the drive.

DESCRIPTION OF THE DRAWING Further features and details of the inventionand advantages obtained thereby will become apparent from the followingdrawing.

The drawing shows the lower part of a grinding mill having a verticalaxis with the grinding bed and its drive represented in axial section.

DESCRIPTION or THE INVENTION A grinding bed or grinding vessel 2 ishorizontally disposed in the housing 1 of a mill. This grinding vessel 2is set in motion about the vertical central axis by a drive means. 0nthe grinding vessel 2 several grinding rollers 3 roll about theirstaionary axles 4, while these axles are under pressure from the of anelectromotor. In the embodiment illustrated, the grind ing bed 2 ismounted upon a grinding vessel support 6 having a circular peripherywhich carries the rotor winding 8 in its lower periphery area 7.

The stator winding 9 of this motor is rigidly disposed in housing 1 andsurrounds rotor 8 in a horizontally extending area.

The grinding vessel support 6 in its turn is journalled in a radialbearing 12 that is mounted in a pedestal 13 of the machine with a plate10 and an axle stud l1 interposed. Furthermore an axial bearing 14 isdisposed between plate 10 and machine pedestal 13.

Due to the direct drive without interposing a transmission; thenecessary space is provided for the aforementioned bearings so thatabove all the axial bearing 14 can be displaced outwardly. The bearings12 and 14 may be constructed in any desired and known manner to meet therequirements of the heavy loads.

Having now described my invention with reference to the embodimentillustrated in the drawing, what I desire to protect tionary axles underdownward pressure, a support extending downwardly from said vessel, apedestal disposed below said support, saidvessel and support definingthe rotor of a motor, a rotor winding extending peripherally about saidrotor, and a stator winding fixedly supported in said housing andextending,

around said rotor winding.

2. Rotor mill drive in accordance with claim 1, including a base belowsaid rotor having a stud extending downwardly therefrom into said base,an axial bearing between said base and said pedestal, and a radialbearing disposed intermediate said stud and said pedestal.

1. Roller mill drive for roller mill of the type having a grindingvessel disposed in horizontal position in a housing for rotation about avertical axis and grinding rollers disposed above said vessel operativein response to rotation of said vessel to roll and grind material, saidrollers being supported on stationary axles under downward pressure, asupport extending downwardly from said vessel, a pedestal disposed belowsaid support, said vessel and support defining the rotor of a motor, arotor winding extending peripherally about said rotor, and a statorwinding fixedly supported in said housing and extending around saidrotor winding.
 2. Rotor mill drive in accordance with claim 1, includinga base below said rotor having a stud extending downwardly therefrominto said base, an axial bearing between said base and said pedestal,and a radial bearing disposed intermediate said stud and said pedestal.